Improvement in steam-generatoks



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.THOMAS BOLT, OF TRIESTE,AUSTRIA.

Letters Patent No. 80,956, dated August 11, 1868; patented inEngland,vJzme 10, 1867.

IMPROVEMENT IN STEAM-GENERATORS.

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'ro ALL WHoM Ir MAY eoNoERN:

Whereas I,"\THOMAS HOLT, of Trieste, in the Empire of Austria, engineer,have invented Improvements in the Construction of Steam-Boilers, I dohereby declare that the following is a full and exact description.

of thesaid improvements. s

The object of this invention is to obtain an increased heating-surfaceinstationary, marine, and locomotive steam-boilers, and at the same timeto 'simplify the construction of such boilers. This end Iattain by theuse of a novel arrangement of attened tubes or chambers,which form thepassages-or dues for the'iiame and heated gases to pass through, whilethe water circulates freely between them. The tubes or chambers are setparallel to each other, and in such relative positions that an easyaccess to theirivets us'ed for lconnecting the tubes or chamberstogether will be provided, and the surfaces of the tubes or chambers, bycontracting and expanding under variations of temperature, will tend toprevent the adhesion of scale or deposit.4

In the accompanying drawings I have shown five diierent arrangements ofboilers with my invention applied thereto, for the purpose ofillustrating the adaptability of the invention to very varyingcircumstances. In constructing a high-pressure land-boiler, I use, bypreference, a cylindrical shell, either vertical, as shown in Sheet I,or horizontal, as shown is Sheet II, and I form a compound central iiuetherein by the use ofthe parallel tubes. v l i In Sheet I, Figure 1shows in central section a vertical high-pressure land-boiler,.ahd

Figure 2 is a transverse section of the same.

Ais a cylindrical shell, closed at top by an inverted cone, which ismade removable, to allow of the withdrawal of the parallel tubes in abody, 'for repairs. At bottom the shellA is extended by a slightlyconical continuation. l B B' are the tube-plates, set parallel to-eachother, but at an incline, for the purpose to be presently explained. Thelower tube-plate, Br, forms the top of the tire-chamber C, the {irc-barsof whichA are shown at D. The water-space of the boiler extends down toa level with. the fire-bars, and it is to the inner casing, A', formingthe perimeter ofthe1'ire-chamber, that the tube-plate B' is secured. v

E are the flattened tubes, set vertically in the middle of theshell ofthe boiler, Aand forming iiues, for the passage upwards of the gases ofcombustion, while they present a large heating-surfacearoundand overwhich the water is' free to circulate.

The construction of these tubes admits of modication, but 'in all casesthe tubes, when rivetedtogether at their opposite ends, must allow of a.free passage between them for the' circulation of water over the greaterportiouof their length. i

Figure 3, Sheet I, shows detached, and inperspecti've, the form of tubewhich I generally prefer to employ, the tube having expanded ends.

Figure 4 is a cross-section oi' the same, showing auarraugenrent' forpreventing the buckling, or retaining the parallelism ofthe sides. i

Figure 5 is aperspective view of two tubes vriveted together. Thesetubes have also expanded ends, but dii'erent means for preventing thebuckling inwardsfof the sidcsoi the tubes.

Figure 6 shows in perspective two tubes made parallel from endto end,andyet riveted together, so as to provide for the free circulation ofWater between them. v

The tubes E may be formed by lattening drawn tubes, or of platesriveted, welded, or braz'ed together at their edges. Figs. 3 and 4 showthe tubesfcomposed of plates, riveted to side-pieces. Within the tubes,at given distances apart, I insert stays, which may be longitudinal, asshown in figs. 5 and 6, or simply ballsplaced in cups, formed at givendistances apartlby indents made in the fiat sides of the tubes, andintended for holding the stays in position. Ribs may also, if preferred,be rolled on the plates used to form the tubes, and the ribs of twoplates being brought together, will form stays requiring no connectionor attachment. This forln of stay is illustrated by Figure 7, which willhereafter be more particularly referred to.

The tubes, however made, are so arranged with respect to each other thattheir extremities will form, when connected together, inclines, the.ends of the tubes from the first4 tothe last being advanced, the onebeyond the other, so asto expose u nd'givc access to'the lines of rivetsby which the adjacent tubes are securely riveted together, and causedtopclose the ends ofthe water-spaces left between the tubes, as shown atfig. 1, Sheet I. l The l group of' tubes thus formed isthen secured tothe tube-plates, whichare properly shaped to receive the group. The formofthe group itself'v will he determined by the space allowedlforit inthe shell, it being understood that the water must circulate around thegroup as well as between the individual'tubes.

In Sheet II, which illustrates the horizontal land-boiler- Figure l is alongitudinal section of the boiler, and

Figure shows in partial front view and in partial transverse section va.pair of horizontal land-boilers.

In this arrangement, the tube-plates form' the ends ofthe cylindricalshell A, and the mouths ofthe tubes are presentedvat the requisite angleto admit of thc ascending llames and heated gases from the replaceturning easily into the rear ends of and passing along the horizontallues to the front.

In order to increase the circulation of the water, I give the horizontaldues a4 cant transversely, as shown at iig. 2, wherein the tubes arerepresented, the one half in cross-section and the other half in endview. The,

' waterfspaces between the tubes being thus transversely on the incline,the escape ot the steam from the raised side will be greatlyfacilitated. The angle best suited in this arrangementv for the turningin of the flame aud heated gases to the ilues at one end, and theirescape at the other,` gives access also to the line of rivets by which Isecure the tubes, the one to the other, and when any tube is` burnedout, it can readily be removed by cutting away the rivet-heads, andreplaced by a new tube.

To facilitate the removal of the compound tubular ues, I make in thebrick-work opposite the tubes a door,

this superheating-chamber at any convenient part thereof.

For improving the evaporating power of marine boilers of theordinaryconstruction, Ipropose to fill the ordinary uc-space with tubesarranged, as described, with respect to'the horizontal land-boiler. Thisarrangement is illustrated in Sheet III, where fig. 1 is a partial frontelevation and partial transversesection, taken in two dierent planes,ofthe marine boiler, and iig. 2 isa longitudinal 'section of the same. cThe ordinary flue-spaces, it will be seen, are-filled with groups of theattened tubes E. The flame and heated gases enter'at the rear ends ofthe tubes, and make their exit atthc front ends, as in Sheet II, to theescape-flue. An incidental advantage of this arrangement of flues isthat the transverse tie-rods H may be passed at any required levelthrough the water-spaces in the groups. l

Another arrangement which I propose to employ in adapting my inventionto marine boilers is shown in Sheet IV, wherein the attened metallicparallel lues are modified in form, and are secured directly to the topof the furnace. Fig. 1 shows the boiler -and furnace in-l longitudinalsection, and iig. 2 is a partial transverse section.` Instead of theflues being open at their opposite ends, one side only of the ues Eisopen, and a divisionis made in them as shown atE, extending to aboutone-halftheir depth. This is most conveniently eected l by forming anindented line in corresponding positions in their side-plates, theindents'being suiiiciently deep to insure the raised surfaces coming 1ncontact, and thus preventing the flame and heated gases from passingbetween the plates at that part. Thus a bridge will be formed in eachHue or chamber E forthe flames to play over, as shown in the drawing.The chambers E are s et up in a Vvertical plane,-and are canted, so asto present their open mouths at an incline to the flame. A. hollow orwater-bridge, I, vforming the roof ofA the front part of the fireplaceC, extends to the bridge or division E in the flue-chambers E, andl theame and gases are thus caused to pass into thechambers, and-burn overthedivisions therein, and escape on the other side of the bidge to theuptake lue. The lips of the chambers are provided with anges, by which,through the lines of rivets, they are conncctcd together, as shown inthe detached view, fig. 7, lShcetl, which represents three such chambersrive ted together; Thediv/ision in the chambers, instead of being formedby indenting the metal of the adjacent plates, as shown in fig, 7, maybemade by inserting a stay-bar therein. V

For securing the series of chambers in place, tie-rods, K, are used,andthe iangesof the chambers are riveted directly to the top of thetire-chamber C. '.lo allow of thc'removal of the chambers from theboiler, the bridge, I, which, being hollow,` is connected at itsopposite sides to the water-spaces, is m-a-de removable, it beingsupported in its place on angle-irons. I I In applying my invention tolocomotive-boilers, I incline the tube-plates B B towards the top of thelirechambcr, and ll the space between the tube-plates with the attencdtube-fines E. These tube-dues I place horizontall Y, and connect themtogether by lines of4 rivets, as in the abovedescribed land-boilers; Ialso cant them on one side to increase the circulation. This arrangementis shown in Sheet V, fig. 1 being a longitudinal section of thelocomotive-boiler and furnace, and g. 2 a transverse section, taken intwo different planes for the purpose of showing the front ends of thetubes, and also the tubes in section. I connect the tubular ues E to thetube-plates by forming lips or lianges on the tube-plates to embrace,the tubes, and to receive rivets which are passed through the sidesofthe tubes. At the top of the tire-box or furnace C, I provide a seriesof vertical flue-chambers, E?, open only at bottom, like those used inthe marine arrangement, Sheet IV. These chambers project upwards throughthe water-space into the steam-space, and afford an increasedheatingsurface to the Water, 'While they serve also to superheat thesteam in the steam-space. These chambers are riveted by means et' their.danges to the top plate of the tire-box, and they are further securedin position by rods, K, pendent from the crown of the steam-chamber.Access to the tubes E-may be obtained in the usual way by a door in thesmoke-box.

Having no'w explained the nature of my invention, I wish it to beunderstood that I elaim-A 1. The combiiiation of the inclined ilues F,dividing-plate E', and the removable diaphragm I, in the marine boiler,as herein described, for the purpose specied. U

2. The combination of the flattened tubeE, composed of metallic plateshaving expanded ends, and braced internally by thefbolts or bars, saidtubes beingvriveted together at their ends to leave water-passagesbetween their adjacent sides, as herein described, for the purposespecified. t

In witness whereof, I, the said THOMAS HOLT, have hereunto set my handand seal, this nineteenth day of Septembexgin the year of our Lord, onethousand eight hundred and sixty seven.

` THOMAS HOLT. [L s] Witnesses EDWARD MANDOLIN, EDWARD LOGHERI

